I know the places you've seen in Pattaya, all looking busy and successful, which the well established ones probably are, but only after years of hard graft.
The Thai rules of business for expats, employment laws would be another factor to consider.
I'm a fan of Cheap Charlies IMHO they do a good job on service and food and I've often sat there after a meal day dreaming, thinking I could have done that better, then reality steps in, it's a tough business not for the feint hearted.